The threshold for American intervention in the Syrian conflict has been passed. Only the debate remains about the type of military response to the chemical attack mounted by elements within Syria's regime on 21 August, which murdered 1,000-plus people. This debate must not limit itself to tactical and political considerations alone. Strategic goals are imperative.

President Obama's declared "red line" has been crossed by the Bashar al-Assad dictatorship's sarin and VX assault. The Obama administration now contemplates a militarily strike on Syria for its transgression. But the blow, if press reports are borne out, will be so circumscribed that it will not secure US goals in the ongoing sectarian war. The president spoke of a "shot across the bow" to Assad. Administration officials have ruled out anything approaching "regime change".

Even a scaled-down strike, using only cruise missiles (risking no pilots), ran into unanticipated headwinds, when the British Parliament voted against a military offensive on Syria. As America's closest ally, Britain's decision will at the very least complicate the president's diplomacy and encourage his domestic critics. But shouldn't American military operations be undertaken anyway for strategic reasons, not just as a slap-on-the-wrist punishment or any dubious deterrent effect they may have?

All of the White House's hesitancy and caution is predicated on avoiding what its previous occupant wrought by fighting two wars in the greater Middle East – Iraq and Afghanistan. Such a course of action, or rather inaction, enjoys high approval in most nationwide polls. But will America's standoffishness prove sound in the longer run?

The acid test for any Syrian operations should be whether they further American and western interests, which include countering Iran's malevolent ambitions and checking the expansion of al-Qaida-linked terrorist networks. Tehran is deeply committed to Damascus as a satellite and land corridor to its proxy Hezbollah, the terrorist movement based in Lebanon. In turn, Hezbollah props up Assad's rule, while destabilizing the Levant and threatening Israel and US Arab allies. It is hard to see an unchecked Iran-Syrian-Hezbollah axis acting to stabilize the Middle East.

As the bloody Syrian civil war has persisted, it has acted as a magnet attracting young men far and wide who aspire to be jihadis and to construct a strict Islamic state. Such an enterprise will in time turn its attention and violence on the west. Earlier US intervention, when the political and military tides ran strongly against an on-the-ropes Assad, could well have forestalled the flood of extremist elements who now plague the Levantine country. It is prudent to recognize these realties and to tailor a strategy to contain and combat the spread of Iranian belligerency and Islamist terrorism. Such an endeavor must take account of the looming realities in the irreparably broken Syrian state.

At this juncture, it seems that the two-and-a-half-year Syrian conflict will result in a permanently fractured state, much as what took place within the former Yugoslavia during the 1990s when that post-first world war artificial construct broke up along religious, ethnic and nationalistic lines. What will the post-Syrian territory look like? An outline is emerging. The Syrian northeast is home to a Kurdish enclave, whose people makes no secret of the desire to join with their brethren in Iraq and other Kurdish islands in Turkey and Iran.

The rump-state of Damascus and lands to the west and north, which are populated by Alawites (an offshoot from Iran's Shiite population), will stay tight with Teheran for security and sectarian reasons. One explanation for the Assad regime's desperate resort to deadly gassing stems from its goal to "cleanse" the Damascus suburbs of rebels so as to consolidate its hold on lands surrounding the capital. Such actions portend an Assad goal to endure in a shrunken state – a similar objective also pursued by Serbia's Slobodan Milosevic when he gave up his Greater Serbian ambitions in a collapsing Yugoslavia.

Other sectors of the disintegrating Syrian entity (also thrown together after the first world war but under temporary French rule) include mini-states populated by the Sunni peoples who make up some 70% of the country. These communities differ on the degree of Islam that they want in their lives. Some are more secular than others. This latter group has a mania for rigid Islamic rules. These differing religious orientations have led to intra-Sunni clashes among religious moderates and extremists, as foreign fighters have flocked in and exacerbated religious tensions in their pursuit of an Islamic caliphate. There is a better than even chance that al-Qaida-linked militants will take up violence against Westerners and the west at some future time.

A realistic assessment of this emerging checker-board of political entities thus behooves American policies and military operations to buttress those polities, which the United States can align to its strategic vision. Nothing will put the Syrian state together again. Nor will the present disengagement in Syria's affairs further America's confrontation with Iran or its fight against al-Qaida-styled terrorist operatives. Limited actions – airstrikes, air-exclusion zones, covert assistance – can spare America another full-scale intervention and occupation in the Middle East.

Washington is already utilizing such limited military engagement in Yemen, Somali and North Africa to beat back al-Qaida affiliates. Far better to assist local allies and proxies for the defense of American interests and allies in this new 30-year war than stand aside with the vain hope it will resolve itself in a manner conducive to American and western priorities.